Separation of monoethanol amine from admixtures by azeotropic distillation with chlorobenzene



Patented Sept. 14, 1948 SEPARATION OF MONOETHANOL AMINE FROM ADM'IXTURES BY AZEOTROPIC DISTILLATION WITH CHLOROBENZENE .lohn C. Speck, J r., Bloomington, Ind., assignor to the United States of America as represented by the Secretary of the Navy No Drawing. Application March 26, 1946, Serial No. 657,329

3 Claims. (01.202-42) This invention relates to a method for separating one component from a mixture with one or more other components by the principle of azeotropism; in particular, it relates to a method of separating 'monoethanolamine (MEA) from admixture with diethanolamine (DEA) and thiethanolamine (TEA) by the addition to the admixture of a component which forms an azeotrope with the monoethanolamine.

It is therefore an object of this invention to provide a method for the separation of MEA from admixture with DEA and TEA, and

It is also an object of this invention to provide a method for the separation of MEA from admixture with DEA and TEA which is based upon the principle of azeotroplsm, and

It is a further object of this invention to provide a method for the separation of MEAstrom admixture with DEA and TEA which is based upon the principle of azeotropism in which the azeotrope 'distills out of the admixture at a boiling point lower than that of any of the components.

with these objectives in view, this inventor has provided a method for the separation of MEA y from DEA and TEA which is based upon the fact that monochlorobenzene forms an azeotrope with MEA but not with DEA or TEA. This azeotrope distills from admixture with the other components at a boiling point of 124 C. This is a lower boiling point than that of any of the components.

The ,boiling points of the azeotrope components at 760 mm. Hg pressure are:

'' C. MEA 1'12 Monochlorobenzene 132 Azeotrope 124 The boiling point at 760 mm. pressure of DEA is 268 centigrade while that of TEA is 278 centigrade at 150 mm. Kg pressure.

The following test runs were made in veriilcation of'the method herein described and claimed.

A 5 to 6 gm. sample oi the DEA and MEA was Per cent MEA Known Mixture as determined (MEA and DEA) by Titration of Per cent MEA Areotropic Distillate Further test runs were made using pure DEA with chlorobenzene which resulted only in chlorobenzene being found in the distillate. The same was true of the test runs on pure TEA and also in a mixture of equal parts of DEA and TEA. In

all three cases only chlorobenzene was found in the distillate. The procedure was also found to be satisfactory when applied to the analysis of commercial samples of DEA which contained MEA as an impurity.

I claim:

1. The method of separating monoethanolamine from admixture with diethanolamine and triethanolamine comprising the addition to the admixture of monochlorobenzene which is characterized by the ability to form an azeotrope with monoethanolamine' and distilling the azeotrope out from the admixture.

2. The method of separating monoethanolamine from admixture with diethanolamine and triethanolaminecomprising the addition to the admixture of monochlorobenzene which is characterized by the ability to form an aaeotrope with monoethanolamine, heating the admixture to a temperature of approximately 124 0. whereby the azeotrope distills out from the admixture and the residual components are rendered substantially pure. a

3. The method of separating monoethanolamine from a mixture containing diethanolamine. consisting in adding monochlorobenzene to ilorm an'azeotrope with the monoethanolamine, and

then distilling out the azeotrope.

I JOHN c. sracx. Ja. REFERENCES crran The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,091,636 Herold et al Aug. 81,198? .60 Andrews et a1. Aug. 9, i988 

